May 6 (Bloomberg) -- Siena prosecutors are seeking to
overturn a judge’s ruling that rejected their request to seize
assets held by Nomura Holdings Inc. as part of an inquiry into
Banca Monte dei Paschi di Siena SpA’s use of derivatives to hide
losses.

Magistrates filed an appeal in Siena today, according to
Giuseppe Grosso, a prosecutor involved in the case. They are
seeking authorization from the appeals court to seize as much as
1.95 billion euros ($2.6 billion) of Nomura assets, as well as
funds belonging to former managers of the Italian lender.

The prosecutors are investigating claims that Nomura
executives colluded with Monte Paschi’s former managers to
design one of two derivatives in 2008 and 2009 that hid as much
as 557 million euros of losses at the Italian bank.

A Siena judge on April 26 turned down the prosecution’s
asset-freeze request, arguing there was no fraud because Monte
Paschi’s senior managers were aware of the transactions and
their implications, a court filing shows. The judge also said
that allegations of usury aren’t founded because Monte Paschi
wasn’t under financial strain.

Tokyo-based Nomura, which isn’t under investigation, said
last month that it will “vigorously” contest any suggestion of
wrongdoing.